ADA and respiratory system disorder: Serum ADA levels were significantly higher in PTB patients compared to healthy controls (SMD = 3.15, 95% CI: [2.51-3.79], <i>p</i> < 0.0001) and other respiratory diseases (SMD = 2.06, 95% CI: [1.38-2.74], <i>p</i> < 0.0001).